This invention relates generally to absorbent articles for absorbing body fluids and exudates. More particularly, the present invention relates to a method for forming absorbent pad assemblies and associated absorbent articles having improved leak prevention and/or fluid flow control.
A wide variety of types of structures are known in the art for use in or as absorbent articles, particularly disposable absorbent articles, used to collect various body fluids and exudates. Commercial absorbent articles include diapers, adult incontinence products, sanitary napkins and bandages. Disposable products of this type generally comprise components for receiving, absorbing and retaining fluids. Typically, the components of such articles include a liquid permeable topsheet, an absorbent core and a liquid impermeable backsheet.
The components of typical absorbent articles are commonly plied or arranged in a horizontal fashion with a major planar surface facing the fluid intake area, e.g., the body of the wearer. In such absorbent articles, the nature or make-up of the fluid communicating therethrough can and typically will change as such fluid traverses though the horizontal ply or plies. Thus, such absorbent articles may experience undesirable horizontal dependency between components. Further, the fibers which customarily make-up the absorbent core are often orientated randomly with fibers within a mat in a lateral neighboring arrangement such that the fluid intake typically wicks in a radial fashion or pattern.
One of the main objectives in the development of absorbent articles is to increase, improve or maximize utilization of the absorbent capacity of the article. In general, products of the type described above typically distribute liquids deposited on the topsheet in a circular pattern. Since such structures generally have a length that exceeds their width, this may undesirably result in the fluids, e.g., exudates, reaching the longitudinal side edges of the absorbent article prior to the desirable utilization of the absorbent capacity at the end regions of the absorbent article. As will be appreciated, such occurrence may undesirably increase the possibility or likelihood of leakage from the sides of the article despite the availability of unutilized or underutilized absorbent capacity in the end regions of the absorbent article.
Moreover, such absorbent articles can and may be subjected to a wide range of conditions and applications such as due to factors inherent or related to the environment in which the article is utilized. Thus, the fluids which may need to be absorbed thereby may vary in properties or parameters such as including flow rate as well as form, phase or composition. For example, exudates may be multiphasic and heterogeneous, such as in the case of menses which may include red blood cells, mucin, plasma and tissue debris, for example.
Sanitary napkins (also referred to as catamenial pads), feminine pads, overnight pads, panty liners and panty shields are designed to be worn by a female to absorb menses and other body fluids discharged before, during and after a menstrual period. Sanitary napkins are external devices which are designed to be aligned approximate the pudendum region of a human body and are generally held in position by being adhesively or mechanically attached to an undergarment. Sanitary napkins also typically differ from panty liners and panty shields in several notable ways. Sanitary napkins are generally larger in size and have a more defined 3-dimensional configuration, are thicker in caliper and have a greater fluid capacity than panty liners or panty shields.
In view of the desire to provide increased comfort to the wearer and to minimize the appearance of the presence of such absorbent articles there is an ongoing demand and need for smaller or less bulky absorbent articles. Thus, there is a need and a demand for improved absorbent pad assemblies and absorbent articles such as may result in more complete utilization of the absorbent capacity thereof and such as may more effectively and efficiently respond to the possibly wide range of operating and performance conditions to which such assemblies and articles can be exposed. More particularly, there is a need and a demand for absorbent pad assemblies and absorbent articles which have improved control or management of fluid flow in association therewith.
A general object of the invention is to provide a method for forming absorbent structures such as either or both an improved absorbent pad assembly and absorbent article.
A more specific objective of the invention is to overcome one or more of the problems described above.
The general object of the invention can be attained, at least in part, through a method involving adjacently disposing at least a first generally planar fluid conveyance barrier member of preselected permeability between at least first and second absorbent members and orientating the adjacently disposed barrier member and first and second absorbent members wherein each of the first and second absorbent members has a ratio of horizontal width to vertical height of no more than about 10:1.
The prior art generally fails to provide absorbent pad assemblies and absorbent articles which make as complete or fall utilization of the absorbent capacity thereof as may be desired. The prior art also generally fails to provide absorbent pad assemblies and absorbent articles which can respond to the possibly wide range of operating and performance conditions to which such assemblies and articles can be exposed and to do so in an as effective and efficient a manner as may be desired.
The invention further comprehends a method for forming an absorbent pad assembly. In accordance with one preferred embodiment of the invention, such a method involves horizontally layering at least a first generally planar fluid conveyance barrier member of preselected permeability between first and second absorbent members and vertically reorientating the horizontally layered barrier member and first and second absorbent members.
In accordance with another embodiment, the invention still further comprehends a method for improving the fluid management by an absorbent article which includes a liquid pervious cover, a liquid impervious backsheet and an absorbent pad assembly disposed between the cover and the backsheet. The method involves the utilization of an absorbent pad assembly including a first generally planar fluid conveyance barrier member having a preselected permeability interposed between a pair of absorbent members generally perpendicularly disposed relative to the contact surface. As described in greater detail below, one particular form of such an absorbent article is a sanitary napkin.
Another aspect of the invention relates to specific absorbent structures. One such absorbent structure is a specific absorbent pad assembly which includes at least a first generally planar fluid conveyance barrier member of preselected permeability interposed between first and second vertically orientated absorbent members.
Another specific absorbent structure in accordance with such aspect of the invention has a contact surface and includes an absorbent pad assembly which includes at least first and second generally planar fluid conveyance barrier members. Each of the barrier members has a preselected permeability and is interposed between a pair of absorbent members which are generally perpendicularly disposed relative to the contact surface.
As used herein, references to xe2x80x9cabsorbent article(s)xe2x80x9d are to be understood to refer to products such as diapers, sanitary napkins, training pants, incontinent garments, overnight pads, panty liners, under arm shields and the like, which are used to absorb body fluids and exudates, such as urine, menses, blood, perspiration and other excrements discharged by the body.
Further, references herein to absorbent members as being xe2x80x9cvertically orientatedxe2x80x9d are to be understood to refer to the general disposition of the member and are in general reference relative to the body contacting surface or face of the absorbent article itself. In general, vertically orientated absorbent members are to be understood as having a ratio of horizontal width to vertical height of no more than about 10:1, preferably no more than about 5:1 and, more preferably about 1:1 or less.
References herein to adjacent absorbent members as being xe2x80x9cnoncontinuousxe2x80x9d are to be understood to refer to such adjacent absorbent members as forming or having a surface interface therebetween. As will be appreciated, such a surface interface may, in practice, serve to hinder, prevent or avoid fluid passage between or from one to another of the adjacent absorbent members. As will be appreciated and as described in greater detail below, adjacent absorbent members will preferably differ in one or more property or characteristic such as chemical composition or construction such as fiber orientation or thickness, for example. Other effective properties or characteristics by which adjacent absorbent members may differ will be apparent to those skilled in the art and guided by the teachings herein provided.
References herein to adjacent absorbent members as forming a xe2x80x9csurface interfacexe2x80x9d therebetween are to be understood as referring to the formation between adjacent members of a surface at which the adjacent members contact or are in proximity to each other.
References herein to xe2x80x9ccontact surfacexe2x80x9d are to be understood as referring to that surface of the absorbent member, pad assembly, article or the like with which the fluid to be absorbed initially contacts.
Other objects and advantages will be apparent to those skilled in the art from the following detailed description taken in conjunction with the appended claims and drawings.